Note: Descriptions are shown in the official language in which they were submitted.
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DISPOSABLE ABSORBENT ARTICLE HAVING
FECAL MANAGEMENT MEMBER
FIELD OF THE INVENTION
The present invention relates to articles which absorb andlor contain
bodily exudates, including disposable absorbent articles such as diapers,
adult
incontinence products, sanitary napkins and the like. More particularly, the
invention relates to disposable absorbent articles which have the capacity to
retain low-viscosity fecal material away from the skin of the wearer, in order
to
reduce leakage and make it easier to clean the wearer when the soiled
disposable absorbent article is removed.
BACKGROUND OF THE INVENTION
Disposable absorbent articles such as diapers and adult incontinence
product are well known in the art. Such disposable absorbent articles collect
and retain urine and fecal material deposited thereon by the wearer.
To date, most attempts in the art to handle the urine and fecal material
collected and retained in the disposable absorbent article have been directed
to
handling urine. Dealing with fecal material collected by the disposable
absorbent article is simply more difficult than dealing with urine, due to the
complex Theology of low-viscosity material.
Exemplary of the urine handling prior art are several attempts to provide
disposable absorbent articles having a first topsheet which faces towards and
contacts the body of the wearer, and a secondary topsheet under the first
topsheet, which either absorbs urine, or transfers the urine to an underlying
core
for storage until the disposable absorbent article is removed from the wearer.
Typically, the first topsheet and secondary topsheet have different
material properties. The secondary topsheet may have a smaller pore size than
the first topsheet, to assist in transfer of the urine through the topsheet.
The first
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topsheet may be hydrophobic and more resilient when wetted than the
secondary topsheet, in order to pass fluids through the first topsheet to the
secondary topsheet.
In yet another attempt in the prior art, the disposable absorbent article
has a first topsheet, secondary topsheet and core. The secondary topsheet
consists essentially of meltblown hydrophilic fibers and has a pore size
greater
than the pore size of the core. This arrangement allegedly allows the
secondary
topsheet to rapidly receive multiple liquid insults and distribute the liquid
in the
X-Y plane prior to absorption by the core. In yet another attempt, improved
vertical wicking capability for urine has been allegedly achieved using
inflated
cellulose fibers which are free of a surface finish or are crosslinked to one
another.
In another attempt in the prior art, an absorbent core suitable for
acquiring and containing liquids such as urine in a particularly effective and
efficient manner comprises multiple layers. The first layer, which is closest
to the
wearer, comprises hydrophilic fibrous material and has an acquisition zone of
a
relatively lower average density than other portions of this layer, in order
to
quickly acquire discharged liquids. Below the first layer is a liquid handling
layer
comprising a resilient, low density high void volume material that is moisture
insensitive in order to rapidly acquire liquid insults into itself through the
acquisition zone and distribute these liquids throughout the liquid handling
layer
to a storage layer. The storage layer comprises a combination of fibrous
material and discrete particles of absorbent gelling material, and allows the
liquid handling layer to be drained of the liquids it has acquired, so that
the
liquid handling layer may have sufficient capacity to acquire and distribute
subsequent loadings of liquids.
Examples of such attempts in the prior art include U.S. Patents 4,047,531
issued September 13, 1977 to Karami; 4,798,603 issued January 17, 1989 to
Meyer et al.; 5,037,409 issued August 6, 1991 to Chen et al.; 5,124,197 issued
June 23, 1992 to Bernardin et al.; and 5,134,007 issued July 28, 1992 to
Reising et al.
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Of course, absorbent gelling materials are also now well known in the
prior art for their urine handling capability. Absorbent gelling materials are
polymeric materials capable of absorbing large quantities of fluids, such as
. urine, and retaining such absorbed fluids under moderate pressure. The
effectiveness of the absorbent gelling materials is quite dependent upon the
form, position, and weight percentage of the absorbent gelling materials which
are incorporated into the core of the disposable absorbent article.
Recent attempts have been made in the art to provide absorbent gelling
materials which have the ability to swell against pressure. These teachings
allege to provide the advantage that the absorbent gelling materials absorb
fluid
under actual pressures exerted by the body during use. Yet other teachings in
the art provide absorbent gelling materials having a particular free swell
rate
and absorbency under load. Alleged advantages of such an absorbent gelling
materials are lower volume and mass with approximately the same absorbent
capacity, the ability to rapidly absorb a discharged liquid under pressures
typically encountered during use, and the ability to retain the absorbed
liquid
under pressures typically encountered during use.
Examples of such attempts in the prior art include U.S. Patents 5,147,343
issued September 15, 1992 to Kellenberger and 5,149,335 issued September
22, 1992 to Kellenberger et al.
However, all of these attempts to handle urine do little, if anything, to
improve handling of low-viscosity fecal material which may also be present in
the disposable absorbent article. Attempts to deal with fecal material include
providing a first topsheet which conforms closely to the wearer and has an
aperture. The aperture is hopefully registered with the anal opening, so that
fecal material passes therethrough into a void space. The first topsheet may
comprise various elastic panels in order to closely conform to the skin of the
wearer, andlor may have linear elastic strands. improvements have been made
in this area of the prior art, such as optimizing the material properties of
the first
topsheet. Such optimization makes the first topsheet more comfortable to the
wearer and allows a single disposable absorbent article to fit a larger range
of
sizes of wearers.
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Yet other attempts have been made in this area of the prior art to provide
an absorbent core with a hole therein, in order to receive the fecal material.
The
hole may be oblate shaped, so that it is longer and narrower than the aperture
in
the first topsheet, or may be diamond shaped. The hole in the core may be
positioned below an aperture which has elastic strips around its edge.
Improvements to this genre of the prior art disposable absorbent articles
also include the addition of spacers. Spacers may be interposed between the
first topsheet and the core, in order to ensure a void space is present to
receive
the fecal material.
Yet other attempts have been made in this genre of the prior art to
provide barriers which limit the movement of fecal material to particular
portions
of the disposable absorbent article: The barriers limit the contact of the
fecal
material to a lesser portion of the skin of the wearer, than a comparable
disposable absorbent article which has no barriers.
Still other attempts in the prior art provide barrier leg cuffs which are
upstanding from the plane of the topsheet. The barrier leg cuffs prevent fecal
material from breaching the perimeter of the disposable absorbent article.
Examples of such attempts to handle fecal material include U.S. Patent
4,892,536 issued January 9, 1990 to DesMarais et al.; U.S. Patent 4,909,803
issued March 20, 1990 to Aziz et al.; U.S. Patent 4,968,312 issued November 6,
1990 to Khan; commonly assigned U.S. Patent 4,990,147 issued February 5,
1991 to Freeland; commonly assigned U.S. Patent 5,037,416 issued August 6,
1991 to Allen et al.; U.S. Patent 5,062,840 issued November 5, 1991 to Holt et
al.; commonly assigned U.S. Patent 5,171,236 issued December 15, 1992 to
Dreier et al.; and European Patent Application 0,355,740 A2 published February
28, 1990 to Enloe.
However, none of these attempts to handle fecal material solve the
problem of low-viscosity fecal material which is prevalent in younger
children,
particularly those who are breast fed. Low-viscosity fecal material easily
migrates within the disposable absorbent article under the influences of
gravity
and motion or pressure by the wearer.
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The migration of the fecal material often moves it towards the perimeter
- of the disposable absorbent article, increasing the likelihood of leakage.
The
. migration of the fecal material also smears it against the skin of the
wearer,
making cleanup more difficult. In order to clean the wearer, the caretaker
must
wipe the entire area of the skin which has encountered the fecal material and
typically has to deal with a relatively large soiled area.
One attempt in the art to handle low-viscosity fecal material is found in
U.S. Patent Application Serial No. 08107fi,713 filed June 11, 1993 in the name
of Roe. This application is a disposable absorbent article having a first
topsheet
with a high traps-topsheet penetration overlaying a secondary topsheet having
a
lesser traps-topsheet penetration.
Accordingly, it is an object of this invention to provide a disposable
absorbent article which reduces leakage of fecal material from the disposable
absorbent article and minimizes the amount of low-viscosity fecal material
remaining on the skin of the wearer once the disposable absorbent article is
removed. It is further an object of this invention to provide a disposable
absorbent article which separates the fecal material into components.
SUMMARY OF THE INVENTION
The present invention is directed to a disposable absorbent article. The
disposable absorbent article comprises a backsheet and a fecal management
member joined to the backsheet either directly or indirectly. The fecal
management member comprises a backing and a sheet of fibers. The sheet of
fibers have anchor portions in the backing at spaced bonding locations and
have arcuate portions of the sheet projecting from the backing between bonding
locations. The backing of the fecal management member comprises a scrim.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctly claiming the subject matter which is regarded as the present
invention,
it is believed that the description will be better understood from the
following
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descriptions which are taken in conjunction with the accompanying drawings in
which like designations are used to designate substantially identical
elements.
Figure 1 is a plan view of an absorbent article embodiment of the present
invention having portions cut away to reveal the underlying structure, the
garment-facing surface of the diaper facing the viewer.
Figure 2 is a perspective illustration of a fecal management member of
the present invention.
Figure 3 is a schematic illustration of a method and equipment for making
the fecal management member of the present invention.
Figure 4 is a schematic illustration of a method and equipment for making
the fecal management member of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term "absorbent article" refers to devices which
absorb and contain body exudates, and more specifically, refers to devices
which are placed against or in proximity to the body of the wearer to absorb
and
contain the various exudates discharged from the body. The term "disposable"
is used herein to describe absorbent articles which generally are not intended
to
be laundered or otherwise restored or reused as an absorbent article (i.e.,
they
are intended to be discarded after a single use and, preferably, to be
recycled,
composted or otherwise disposed of in an environmentally compatible manner).
(As used herein, the term "disposed" is used to mean that an elements) of the
.
diaper is formed (joined and positioned) in a particular place or position as
a
unitary structure with other elements of the diaper or as a separate element
joined to another element of the diaper. As used herein, the term "joined"
encompasses configurations whereby an element is directly secured to another
element by affixing the element directly to the other element, and
configurations
whereby an element is indirectly secured to another element by affixing the
element to intermediate members) which in turn are affixed to the other
element.) A "unitary" absorbent article refers to absorbent articles which are
~
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formed of separate parts united together to form a coordinated entity so that
they do not require separate manipulative parts like a separate holder and
liner.
The disposable absorbent article of the present invention comprises a
backsheet and a fecal management member. In one embodiment of the present
invention, the disposable absorbent article additionally comprises a topsheet
joined to the backsheet.
The topsheet may cover a portion of the fecal management member such
that this portion of the fecal management member is positioned intermediate
the
topsheet and the backsheet. The topsheet may also cover the whole of the fecal
management member.
Alternatively, the fecal management member of the present invention may
act as a topsheet. The fecal management member may act as a topsheet over
the whole of the diaper or only over a portion of the of the diaper with a
conventional topsheet covering the remaining portion of the diaper.
The disposable absorbent article of the present invention preferably
comprises an absorbent core which is positioned between the fecal
management member and the backsheet.
A preferred embodiment of an absorbent article of the present invention
is the unitary disposable absorbent article, diaper 20, shown in Figure 1. As
used herein, the term "diaper" refers to an absorbent article generally worn
by
infants and incontinent persons about the lower torso. The present invention
is
also applicable to other absorbent articles such as incontinence briefs,
incontinence undergarments, absorbent inserts, diaper holders and liners,
feminine hygiene garments, and the like.
Figure 1 is a plan view of a diaper 20 of the present invention in a flat-
out, state with portions of the structure being cut-away to more clearly show
the
construction of the diaper 20. The portion of the diaper 20 which faces the
wearer is oriented towards the viewer. As shown in Figure 1, the diaper 20
preferably comprises a liquid pervious topsheet 24; a liquid impervious
backsheet 26; an absorbent core 28, which is preferably positioned between at
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least a portion of the topsheet 24 and the backsheet 26; a fecal management
member 29 positioned between the topsheet 24 and the absorbent core 28; side
panels 30; elasticized leg cuffs 32; an elastic waist feature 34; and a
fastening
system generally designated 40. Diaper 20 is shown in Figure 1 to have a front
waist region 36, a rear waist region 38 opposed to the front waist region 36
and
a crotch region 37 located between the front waist region and the rear waist
region. The periphery of the diaper 20 is defined by the outer edges of the
diaper 20 in which the longitudinal edges 50 run generally parallel to the
longitudinal centerline 100 of the diaper 20 and the end edges 52 run between
the longitudinal edges 50 generally parallel to the lateral centerline 110 of
the
diaper 20.
The chassis 22 of the diaper 20 comprises the main body of the diaper
20. The chassis 22 comprises at least a portion of the absorbent core 28 and
ferably an outer covering layer including the topsheet 24 and the backsheet
26. if the absorbent article comprises a separate holder and a liner, the
chassis
22 generally comprises the holder and the liner. (For example, the holder may
comprise one or more layers of material to form the outer cover of the article
and the liner may comprise an absorbent assembly including a topsheet, a
backsheet, and an absorbent core. In such cases, the holder andlor the liner
may include a fastening element which is used to hold the liner in place
throughout the time of use.) For unitary absorbent articles, the chassis 22
comprises the main structure of the diaper with other features added to form
the
composite diaper structure. While the topsheet 24, the backsheet 26, and the
chassis 22 may be assembled in a variety of well known configurations,
preferred diaper configurations are described generally in U.S. Patent
3,860,003
entitled "Contractible Side Portions for Disposable Diaper" which issued to
Kenneth B. Buell on January 14, 1975; and U.S. Pat. No. 5,151,092 issued to
Buell on September 9, 1992; and U.S. Pat. No. 5,221,274 issued to Buell on
June 22, 1993. Other suitable diaper chassis design are disclosed in U.S. Pat.
No. 5,569,232 entitled "Absorbent Article With Multiple Zone Structural
Elastic-
Like Film Web Extensible Waist Feature" which issued to Roe et al. on October
29, 1996; U. S. Pat. No. 5,554,144 entitled "Absorbent Article With Multiple
Zone
Structural Elastic-Like Film Web Extensible Waist Feature" which issued to Roe
et aI. on September 10, 1996; U.S. Pat. No. 5,554,143 entitled "Absorbent
Article With Multiple Zone Structural Elastic-Like Film Web Extensible Waist
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Feature" which issued to Roe et al. on September 10, 1996; U.S. Pat. No.
5,554,145 entitled "Absorbent Article With Multiple Zone Structural Elastic-
Like
Film Web Extensible Waist Feature" which issued to Roe et al. on September
10, 1996; U.S. Pat. No. 5,556,394 entitled "Absorbent Article With Multiple
Zone
Structural Elastic-Like Film Web Extensible Waist Feature" which issued to Roe
et al. on September 17, 1996. Each of these references is hereby incorporated
by reference herein.
The backsheet 26 is generally that portion of the diaper 20 positioned
adjacent the garment facing surface 45 of the absorbent core 28 which prevents
the exudates absorbed and contained therein from soiling articles which may
contact the diaper 20, such as bedsheets and undergarments. In preferred
embodiments, the backsheet 26 is impervious to liquids (e.g., urine) and
comprises a thin plastic film such as a thermoplastic film having a thickness
of
about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Suitable backsheet
films
include those manufactured by Tredegar Industries Inc. of Terre Haute, IN and
sold under the trade names X15306, X10962 and X10964. Other suitable
backsheet materials may include breathable materials which permit vapors to
escape from the diaper 20 while still preventing exudates from passing through
the backsheet 26. Exemplary breathable materials may include materials such
as woven webs, nonwoven webs, composite materials such as film-coated
nonwoven webs, and microporous films such as manufactured by Mitsui Toatsu
Co., of Japan under the designation ESPOIR NO and by EXXON Chemical Co.,
of Bay City, TX, under the designation EXXAIRE. Suitable breathable composite
materials comprising polymer blends are available from Clopay Corporation,
Cincinnati, OH under the name HYTREL blend P18-3097. Such breathable
composite materials are described in greater detail in PCT Application No. WO
95116746, published on June 22, 1995 in the name of E. I. DuPont and
copending U.S. Patent Application Serial No. 081744,487, filed on November 6,
1996 in the name of Curro. Other breathable backsheets including nonwoven
webs and apertured formed films are described in U.S. Pat. No. 5,571,096
issued to Dobrin et al. on November 5, 1996. Each of these references is
hereby
incorporated by reference herein.
The backsheet 26, or any portion thereof, may be elastically extensible in
one or more directions. In one embodiment, the backsheet 26 may comprise a
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structural elastic-like film ("SELF") web. A structural elastic-like film web
is an
extensible material that exhibits an elastic-like behavior in the direction of
elongation without the use of added elastic materials. The SELF web includes a
strainable network having at least two contiguous, distinct, and dissimilar
regions. Preferably, one of the regions is configured so that it will exhibit
resistive forces in response to an applied axial elongation in a direction
parallel
to the predetermined axis before a substantial portion of the other region
develops significant resistive forces to the applied elongation. At least one
of
the regions has a surface-pathlength which is greater than that of the other
region as measured substantially parallel to the predetermined axis while the
material is in an untensioned condition. The region exhibiting the longer
surface-pathlength includes one or more deformations which extend beyond the
plane of the other region. The SELF web exhibits at least two significantly
different stages of controlled resistive force to elongation along at least
one
predetermined axis when subjected to an applied elongation in a direction
parallel to the predetermined axis. The SELF web exhibits first resistive
forces
to the applied elongation until the elongation of the web is sufficient to
cause a
substantial portion of the region having the longer surface-pathlength to
enter
the plane of applied elongation, whereupon the SELF web exhibits second
resistive forces to further elongation. The total resistive forces to
elongation are
higher than the first resistive forces to elongation provided by the first
region.
SELF webs suitable for the present invention are more completely described in
U.S. Patent No. 5,518,801 entitled Web Materials Exhibiting Elastic-Like
Behavior, which issued to Chappell, et, al. on May 21, 1996, which is
incorporated herein by reference. In alternate embodiments, the backsheet 26
may comprise elastomeric films, foams, strands, or combinations of these or
other suitable materials with nonwovens or synthetic films.
The backsheet 26 may be joined to the topsheet 24, the absorbent core
28, the fecal management member 29, or any other element of the diaper 20 by
any attachment means known in the art. For example, ~~e attachment means
may include a uniform continuous layer of adhesive, a patterned layer of
adhesive, or an array of separate lines, spirals, or spots of adhesive. One
preferred attachment means comprises an open pattern network of filaments of
adhesive as disclosed in U.S. Patent 4,573,986 entitled "Disposable Waste-
Containment Garment", which issued to Minetola et al. on March 4, 1986. Other
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suitable attachment means include several lines of adhesive filaments which
are
swirled into a spiral pattern, as is illustrated by the apparatus and methods
shown in U.S. Patent 3,911,173 issued to Sprague, Jr. on October 7, 1975; U.S.
Patent 4,785,996 issued to Ziecker, et al. on November 22, 1978; and U.S.
Patent 4,842,666 issued to Werenicz on June 27, 1989. Each of these patents
are incorporated herein by reference. Adhesives which have been found to be
satisfactory are manufactured by H. B. Fuller Company of St. Paul, Minnesota
and marketed as HL-1258. Alternatively, the attachment means may comprise
heat bonds, pressure bonds, ultrasonic bonds, dynamic mechanical bonds, or
any other suitable attachment means or combinations of these attachment
means as are known in the art.
The topsheet 24 is preferably positioned adjacent the body surface 47 of
the absorbent core 28 and may be joined thereto andlor to the backsheet 26 by
any attachment means known in the art. Suitable attachment means are
described above with respect to means for joining the backsheet 26 to other
elements of the diaper 20. In one preferred embodiment of the present
invention, the topsheet 24 and the backsheet 26 are joined directly to each
other
in some locations and are indirectly joined together in other locations by
directly
joining them to other elements of the diaper 20.
The topsheet 24 is preferably compliant, soft feeling, and non-irritating to
the wearer's skin. Further, at least a portion of the topsheet 24 is liquid
pervious,
permitting liquids to readily penetrate through its thickness. A suitable
topsheet
24 may be manufactured from a wide range of materials, such as porous foams;
reticulated foams; apertured plastic films; or woven or nonwoven webs of
natural
fibers (e.g., wood or cotton fibers), synthetic fibers {e.g., polyester or
polypropylene fibers), or a combination of natural and synthetic fibers. if
the
absorbent assemblies include fibers, the fibers may be spunbond, carded, wet-
laid, meltblown, hydroentangled, or otherwise processed as is known in the
art.
A suitable topsheet may also comprise apertures, the apertures preferably
having a size of at least 0.2mm2. One suitable topsheet 24 comprising a web of
staple length polypropylene fibers is manufactured by Veratec, Inc., a
Division
of International Paper Company, of Walpole, Massachusetts under the
designation P-8.
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Suitable formed film topsheets are described in U.S. Pat. No. 3,929,135,
entitled "Absorptive Structures Having Tapered Capillaries", which issued to
Thompson on December 30, 1975; U.S. Pat. No. 4,324,246 entitled "Disposable
Absorbent Article Having A Stain Resistant Topsheet", which issued to Mullane,
et al. on April 13, 1982; U.S. Patent 4,342,314 entitled "Resilient Plastic
Web
Exhibiting Fiber-Like Properties", which issued to Radel, et al. on August 3,
1982; U.S. Pat. No. 4,463,045 entitled "Macroscopically Expanded Three-
Dimensional Plastic Web Exhibiting Non-Glossy Visible Surface and Cloth-Like
Tactile Impression", which issued to Ahr, et al. on July 31, 1984; and U.S.
Pat.
No. 5,006,394 "Multilayer Polymeric Film" issued to Baird on April 9, 1991.
Other suitable topsheets 30 are made in accordance with U.S. Pat. Nos.
4,609,518 and 4,629,643 which issued to Curro et al. on September 2, 1986 and
December 16, 1986, respectively, and both of which are incorporated herein by
reference. Such formed films are available from The Procter 8~ Gamble
Company of Cincinnati, Ohio as "DRI-WEAVE" and from Tredegar Corporation
of Terre Haute, Indiana as "CLIFF-T."
Preferably, the topsheet 24 is made of a hydrophobic material or is
treated to be hydrophobic in order to isolate the wearer's skin from liquids
contained in the absorbent core 28. If the topsheet 24 is made of a
hydrophobic
material, preferably at least the upper surface of the topsheet 24 is treated
to be
hydrophilic so that liquids will transfer through the topsheet more rapidly.
This
diminishes the likelihood that body exudates will flow off the topsheet 24
rather
than being drawn through the topsheet 24 and being absorbed by the absorbent
core 28. The topsheet 24 can be rendered hydrophilic by treating it with a
surfactant or by incorporating a surfactant into the topsheet. Suitable
methods
for treating the topsheet 24 with a surfactant include spraying the topsheet
24
material with the surfactant and immersing the material into the surfactant. A
more detailed discussion of such a treatment and hydrophilicity is contained
in
U.S. Pat. No. 4,988,344 entitled "Absorbent Articles with Multiple Layer
Absorbent Layers" issued to Reisin~ et al. on Jan. 29, 1991 and U.S. Pat. No.
4,988,345 entitled "Absorbent Articles with Rapid Acquiring Absorbent Cores"
issued to Reising on Jan. 29, 1991. A more detailed discussion of some
suitable
methods for incorporating surfactant in the topsheet can be found in U.S.
Statutory Invention Registration No. H1670, published on July 1, 1997 in the
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names of Aziz et al. Each of these references is hereby incorporated by
reference herein.
Any portion of the topsheet 24 may be coated with a lotion as is known in
the art. Examples of suitable lotions include those described in U.S. Pat. No.
5,607,760 entitled "Disposable Absorbent Article Having A Lotioned Topsheet
Containing an Emollient and a Polyol Polyester Immobilizing Agent" which
issued to Roe on March 4, 1997; U.S. Pat. No. 5,609,587 entitled "Diaper
Having A Lotioned Topsheet Comprising A Liquid Polyol Polyester Emollient
And An fmmobifizing Agent" which issued to Roe on March 11, 1997; U.S. Pat.
No. 5,635,191 entitled "Diaper Having A Lotioned Topsheet Containing A
Polysilozane Emollient" which issued to Roe et al. on June 3, 1997; and U.S.
Pat. No. 5,643,588 entitled "Diaper Having A Lotioned Topsheet" which issued
to Roe et al. on July 1, 1997. The topsheet may also include or be treated
with
antibacterial agents, some examples of which are disclosed in PCT Publication
No. WO 95124'173 entitled "Absorbent Articles Containing Antibacterial Agents
in the Topsheet For Odor Control" which was published on September 14, 1995
in the name of Johnson. Further, the topsheet 24, the backsheet 26 or any
portion of the topsheet or backsheet may be embossed andlor matte finished to
provide a more cloth like appearance.
The absorbent core 28 may comprise any absorbent material which is
generally compressible, conformable, non-irritating to the wearer's skin, and
capable of absorbing and retaining liquids such as urine and other certain
body
exudates. The absorbent core 28 may be manufactured in a wide variety of
sizes and shapes (e.g., rectangular, hourglass, "T"-shaped, asymmetric, etc.)
and may comprise a wide variety of liquid-absorbent materials commonly used
in disposable diapers and other absorbent articles such as comminuted wood
pulp, which is generally referred to as airfelt. Examples of other suitable
absorbent materials include creped cellulose wadding; meltblown polymers,
including coform; chemically stiffened, modified or cross-linked cellulosic
fibers;
tissue, including tissue wraps and tissue laminates; absorbent foams;
absorbent
sponges; superabsorbent polymers; absorbent gelling materials; or any other
known absorbent material or combinations of materials.
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The configuration and construction of the absorbent core 28 may also be
varied (e.g., the absorbent cores) or other absorbent structures) may have
varying caliper zones, a hydrophilic gradient, a superabsorbent gradient, or
lower average density and lower average basis weight acquisition zones; or may
comprise one or more layers or structures). However, the total absorbent
capacity of the absorbent core 28 should be compatible with the design loading
and the intended use of the diaper 20.
Exemplary absorbent structures for use as the absorbent assemblies are
described in U.S. Patent 4,610,678 entitled "High-Density Absorbent
Structures"
issued to Weisman et al. on September 9, 1986; U.S. Patent 4,673,402 entitled
"Absorbent Articles With Dual-Layered Cores" issued to Weisman et al. on June.
16, 1987; U.S. Patent 4,834,735, entitled "High Density Absorbent Members
Having Lower Density and Lower Basis Weight Acquisition Zones", issued to
Alemany et al. on May 30, 1989; U.S. Patent 4,888,231 entitled "Absorbent Core
Having A Dusting Layer" issued to Angstadt on December 19, 1989; U.S. Pat.
No. 5,137,537 entitled "Absorbent Structure Containing Individualized,
Poiycarboxylic Acid Crosslinked Wood Pulp Cellulose Fibers" which issued to
Herron et al. on August 11, 1992; and U.S. Patent 5,147,345 entitled "High
Efficiency Absorbent Articles For Incontinence Management" issued to Young et
al. on September 15, 1992; U.S. Pat. No. 5,342,338 entitled "Disposable
Absorbent Article For Low-Viscosity Fecal Material" issued to Roe on August
30,
1994. Each of these patents is incorporated herein by reference.
FIG. 2 illustrates a first embodiment of a fecal management member
according to the present invention, generally designated by the reference
numeral 29. Generally the fecal management member 29 is a sheet of loop
material 118 having a backing 120 preferably comprising a thermoplastic
backing layer 122 (e.g., of polypropylene), and a multiplicity of
longitudinally
oriented fibers in a specially formed sheet of fibers 126 having anchor
generally
non-deformed anchor portions 127 bonded by being joined to the backing layer
122 at spaced elongate generally parallel bonding locations 128 that are
continuous in one direction along the backing layer 122 with arcuate portions
130 of the sheet of fibers 126 projecting from the backing layer 122 between
the
bonding locations 128 in continuous rows also extending transversely across
the sheet of loop material 118. The arcuate portions 130 of the sheet of
fibers
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126 have a generally uniform height from the backing layer 122 of greater than
about 0.5 millimeters and preferably greater than about 1.0 millimeters, the
height of the formed sheet of fibers 126 is at least one third, and preferably
one
half to one and one half times the distance between the bonding locations 128,
the individual fibers in the sheet of fibers 126 are less than 25 denier
(preferably
in the range of 1 to 10 denier) in size, and the sheet of fibers 126 without
the
backing 120 has a basis weight in the range of 5 to 300 grams per square meter
(and preferably in the range of 15 to 100 grams per square meter) measured
along the backing layer 122 to provide sufficient open area between the fibers
in
the sheet of fibers 126 along the arcuate portions 130 (i.e., between about 10
and 90 percent open area) to afford ready penetration of fecal material into
the
individual fibers along the arcuate portions 130.
Suitable materials for use as the backing 120 include but are not limited
to scrims. The term "scrim" as used herein refers to a network of fibers or
strands comprising at least two parallel fibers or strands running in a first
direction and at least two parallel fibers or strands running in a second
direction.
At least some of the fibers or strands running in the first direction are
connected
to at least some of the fibers or strands running in the second direction at
the
respective cross-over points. The angle between first and second direction is
at
least 30°, preferably 45°, more preferably 60°, most
preferably 90°. A scrim may
comprise fibers or strands of different shapes, compositions and dimensions.
Preferably, the backing is made of thermoplastic polymers. The backing
120 is preferably a relatively thin layer having a thickness in the range of
about
0.00125 to 0.025 centimeters.
The fibers in the sheet of fibers 126 can be disposed in various directions
with respect to the parallel bonding locations 128 and may or may not be
bonded together at crossover points in the arcuate portions 130; can be
disposed in various directions with respect to the parallel bonding locations
128
with the majority of the fibers in the sheet of fibers 126 (i.e., over 80 or
90
percent) extending in directions at about a right angle to the bonding
locations
128; or all of the individual fibers in the sheet of fibers 126 can extend in
directions generally at right angles to the spaced generally parallel bonding
locations 128.
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Sheet of fibers 126 preferably has a hydrophilicity which is less than the
hydrophilicity of the backing 120. In a preferred embodiment, the sheet of
fibers
themselves have a hydrophilicity gradient wherein the arcuate portions 130
have a hydrophilicity which is less than the hydrophilicity of the bonded
locations 128. Even in this configuration it is preferred that the bonded
locations
128 of the sheet of fibers 126 have a hydrophilicity which is less than the
hydrophilicity of the backing 120.
Preferably the fecal management member 29 is secured to the topsheet
24 in a very minimal extent to preserve the openness of the fecal management
member 29 to allow ready penetration of fecal material. More preferably, the
fecal management member 29 is not secured to the topsheet 24 at all
preserving the openness of the fecal management member 29 and also allowing
the topsheet 24 to separate from the fecal management member 29 creating
additional void space within the disposable absorbent article. However, it is
recognized that the fecal management member 29 should be secured within the
diaper 20 to prevent it from freely moving about. To this end, it is preferred
that
the fecal management member 29 be secured directly to the underlying
absorbent core 28. The fecal management member 29 may be joined to the
absorbent core 28 by any attachment means known in the art. For example, the
attachment means may include a uniform continuous layer of adhesive, a
patterned layer of adhesive, or an array of separate lines, spirals, or spots
of
adhesive. One preferred attachment means comprises an open pattern network
of filaments of adhesive as disclosed in U.S. Patent 4,573,986 entitled
"Disposable Waste-Containment Garment", which issued to Minetola et al. on
March 4, 1986. Other suitable attachment means include several lines of
adhesive filaments which are swirled into a spiral pattern, as is illustrated
by the
apparatus and methods shown in U.S. Patent 3,911,173 issued to Sprague, Jr.
on October 7, 1975; U.S. Patent 4,785,996 issued to Ziecker, et al. on
November 22, 1978; and U.S. Patent 4,842,666 issued to Werenicz on June 27,
1989. Each of these patents are incorporated herein by reference. Adhesives
which have been found to be satisfactory are manufactured by H. B. Fuller
Company of St. Paul, Minnesota and marketed as HL-1258. Alternatively, the
attachment means may comprise heat bonds, pressure bonds, ultrasonic bonds,
dynamic mechanical bonds, or any other suitable attachment means or
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17
combinations of these attachment means as are known in the art. A particularly
preferred attachment means is an adhesive having a hydrophilicity which is
greater than the hydrophilicity of the sheet of fibers 126, more preferably a
hydrophilicity which is also greater than the hydrophilicity of the backing
120.
The fecal management member 29 is shown in F1G. 1 to be positioned in
the rear waist region 38 of the diaper 20. By positioning the fecal management
member 29 at least in the rear waist region 38, the fecal management member
29 is aligned with the wearer's anus where it can be most effective in the
management of fecal material deposited onto the diaper 20. However, the fecal
management member 29 may extend into crotch region 37. The fecal
management member 29 may also extend into the front waist region 36 of the
diaper 20. In some embodiments it may also be desirable to have the fecal
management member 29 extend along the entire longitudinal dimension of the
diaper 20.
In addition to positioning the fecal management member 29 at least in the
rear waist region 38 it is also desirable that the portion of the topsheet 24
positioned within the rear waist region 38 have a sufficient open area to
handle
low-viscosity fecal material.
To be the most effective in the handling of low-viscosity fecal material the
fecal management member must have a lofted open structure. One key
component of this equation is the height of the arcuate portions 130 of the
sheet
of fibers 126 from the backing 120. As mentioned above the arcuate portions
130 of the sheet of fibers 126 have a generally uniform height from the
backing
120 of greater than about 0.5 millimeters and preferably greater than about
1.0
millimeters. While even greater heights would provide excellent handling of
low-
viscosity fecal material, e.g., heights of 5.0 centimeters, such heights would
create unwanted bulk in the diaper which may cause discomfort for the wearer.
The other key component is the resiliency of the fecal management
member 29, more particularly the resiliency of the sheet of fibers 126. In
order to
remain open, the sheet of fibers 126 must have a sufficient resiliency to
withstand the forces of packaging and those applied by the wearer. Preferably,
the sheet of fibers 126 has a resiliency of at least 50% after 30 seconds
under
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an applied force of 100g1cm2, more preferably, the sheet of fibers 126 has a
resiliency of at least 75% after 30 seconds under an applied force of
100g/cm2,
most preferably, the sheet of fibers 126 has a resiliency of at least 85%
after 30
seconds under an applied force of 100g1cm2.
The anchor portions 127 are preferably of such dimension that a planar
circle having a diameter of from about 0.2 millimeters to about 20 millimeters
may be inscribed thereon, more preferably, the anchor portions 127 are
preferably of such dimensit~ -~ that a planar circle having a diameter of from
about 0.2 millimeters to about 10 millimeters may be inscribed thereon, and
most preferably, the anchor portions 127 are preferably of such dimension that
a
planar circle having a diameter of from about 0.2 millimeters to about 5
millimeters may be inscribed thereon.
FIG. 3 schematically illustrates a method and equipment for forming the
fecal management member 29. The method illustrated in FIG. 3 generally
comprises forming longitudinally oriented polymeric fibers into a sheet of
fibers
126, forming the sheet of fibers 126 so that it has arcuate portions 130
projecting in the same direction from the spaced generally parallel anchor
portions 127 of the sheet of fibers 126, and bonding the spaced generally
parallel anchor portions 127 of the sheet of fibers 126 projecting from the
front
surface 123 of the backing 120. This method is performed by providing first
and
second heated corrugating members or rollers 226 and 227 each having an axis
and including a plurality of circumferentially spaced generally axially
extending
ridges 228 around and defining its periphery, with the ridges 228 having outer
surfaces and defining spaces between the ridges 228 adapted to receive
portions of the ridges 228 of the other corrugating member 226 or 227 in
meshing relationship with the sheet of fibers 126 between the meshed ridges
228 and to afford rolling engagement between the ridges 228 and spaces of the
corrugating members in the manner of gear teeth. The corrugating members 226
and 227 are mounted in axially parallel relationship with portions of the
ridges
228 of the corrugating members 226 and 227 meshing generally in the manner
of gear teeth; at least one of the corrugating members 226 or 227 is rotated;
and
the sheet of fibers 126 is fed between the meshed portions of the ridges 228
of
the corrugating members 226 and 227 to generally conform the sheet of fibers
126 to the periphery of the first corrugating member 226 and form the arcuate
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19
portions 130 of the sheet of fibers 126 in the spaces between the ridges 228
of
the first corrugating member 226 and the generally parallel anchor portions
127
of the sheet of fibers 126 along the outer surfaces of the ridges 228 on the
first
corrugating member 226. The formed sheet of fibers 126 is retained along the
periphery of the first corrugating member 226 after it has moved past the
meshed portions of the ridges 228. The backing layer 120 is bonded to the
anchor portions 127 of the sheet of fibers 126 on the end surfaces of the
ridges
228 on the first corrugating member 226 by supplying the backing layer 120
into
a nip between the anchor portions 127 of the sheet of fibers 126 on the
periphery of the first corrugating member 226 and a heating roll 250 which is
heated to thermo-bond the backing layer 120 to the sheet of fibers. After roll
250, the fecal management member 29 is separated from the first corrugating
member 226 and carried partially around the roll 250 and through a nip between
the roll 250 and a pinch roller 260 to complete cooling and solidification of
the
thermoplastic backing layer 120.
The sheet of fibers 126 fed between the meshed portions of the ridges
228 of the corrugating members 226 and 227 can be in the form of yarns
distributed so that the fibers in the sheet of fibers 126 fed between the
meshed
ridges 228 of the corrugating members 226 and 227 are uniformly distributed
across the width of the sheet of fibers 126 and all extend generally
perpendicular to the axes of the corrugating members 226 and 227, or the
fibers
in the sheet of fibers 126 can be disposed in random orientation as in a non
woven web or sheet. Such a nonwoven sheet of randomly oriented fibers 126
with no internal bonding except for the friction between the fibers can be
formed
from loose fibers using a carding machine 270 as illustrated, which nonwoven
sheet of randomly oriented fibers 126 has enough integrity to be fed from the
carding machine 270 into the nip between the corrugating members 226 and
227 (if needed, a conveyer (not shown) could be provided to help support and
guide the non woven sheet of randomly oriented fibers 126 is used, preferably
the first corrugating member 226 has a rough finish (e.g., formed by sand
blasting), the second corrugating member 227 has a smooth polished finish, and
the first corrugating member 226 is heated to a temperature slightly above the
temperature of the second corrugating member 226 so that the nonwoven sheet
of fibers 126 will preferentially stay along the surface of the first
corrugating
member 226 and be carried to the nip between the first corrugating member and
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the cooling roller 250 after passing through the nip between the corrugating
members 226 and 227.
Corrugating members 226 and 227 adapted to have such a sheet of
fibers 126 fed into them can have their ridges 228 oriented generally in the
range of 0 to 90 degrees with respect to their axes, but preferably have their
ridges 228 oriented at 0 degrees with respect to (or parallel to) their axes
which
simplifies making of the corrugating members 226 and 227.
FIG. 4 schematically illustrates another embodiment of a method and
equipment according to the present invention for forming the fecal management
member 140. The method is generally similar and uses much of the same
equipment as is illustrated in FIG. 3 (with similar portions of that equipment
having the same reference numerals) except that a plurality of fibers 190 is
now
extruded in a molten state from a die 240. The roller 250 is now cooled to
support formation of the bonds between the anchor portions 127 of the sheet of
fibers 126 and the backing layer 120. When the fibers 190 are passed through
the nip between first corrugating member 226 and cooling roll 250, the fibers
are
bonded to the anchor portions 127 of the sheet of fibers 126 and the cross-
sectional shape of the fibers 190 is expanded in the cross-direction by the
bonding pressure such that a plurality of cross-links between adjacent fibers
is
formed. By cross-linking the plurality of fibers 190, the scrim backing layer
is
formed.
Preferably, the drives for the corrugating member 226 and 227 and for
the cooling roller 250 are separately controllable so that the cooling roller
250
can be rotated at a surface speed that is the same as or different than the
surface speed of the first corrugating member 226. When the cooling roller 250
and the first corrugating member 226 are rotated so that they have the same
surface speed, the sheet of fibers 126 will have about the same shape along
the
backing 120 as it had along the periphery of the first corrugating member 226
as
is illustrated in FIGS. 2 through 5. When the cooling roller 250 and the first
,
corrugating member 226 are rotated so that the cooling roller has a surface
speed that is slower than the surface speed of the first corrugating member
226
the anchor portions 127 of the sheet of fibers 126 will be moved closer
together
in the backing layer 120 at the nip between the cooling roller 250 and the
first
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corrugating member 226, resulting in greater density of the loop portions 130
along the backing 120 than when the cooling roller 250 and the first
corrugating
member 226 are rotated so that they have the same surface speed. This
technique of increasing the amount of loop portions 130 or the loop population
is useful both to make fecal management members having different numbers of
loop portions 130 per centimeter of backing length using the same equipment,
and to make fecal management members with more loop portions 130 per
centimeter of backing length than could be formed between ridges 228
machined on the corrugating member 226 and 227 because of physical
limitations in machining such ridges 228 close together.
The diaper 20 may also comprise at least one elastic waist feature 34
that helps to provide improved fit and containment. The elastic waist feature
34
is generally intended to elastically expand and contract to dynamically fit
the
wearer's waist. The elastic waist feature 34 preferably extends at least -
longitudinally outwardly from at least one waist edge 62 of the absorbent core
28 and generally forms at least a portion of the end edge 52 of the diaper 20.
Disposable diapers are often constructed so as to have two elastic waist
features, one positioned in the first waist region 36 and one positioned in
the
second waist region 38. Further, while the elastic waist feature 34 or any of
its
constituent elements may comprise one or more separate elements affixed to
the diaper 20, the elastic waist feature 34 may be constructed as an extension
of other elements of the diaper 20, such as the backsheet 26, the topsheet 24,
or both the backsheet 26 and the topsheet 24.
The elastic waist feature 34 may be constructed in a number of different
configurations including those described in U.S. Patent 4,515,595 issued to
Kievit et al. on May 7, 1985; U.S. Patent 4,710,189 issued to Lash on December
1, 1987; U.S. Pat. No 5, 151,092 issued to Buell on September 9, 1992; and
. U.S. Pat. No. 5,221,274 issued to Buell on June 22, 1993. Other suitable
waist
configurations may include waistcap features such as those described in U.S.
Patent 5,026,364 issued to Robertson on June 25, 1991 and U.S. Patent
4,816,025 issued to Foreman on March 28, 1989. All of the above mentioned
references are incorporated herein by reference.
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The diaper 20 may also include a fastening system 40. The fastening
system 40 preferably maintains the first waist region 36 and the second waist
region 38 in an overlapping configuration so as to provide lateral tensions
about
the circumference of the diaper 20 to hold the diaper 20 on the wearer. The
fastening system 40 preferably comprises tape tabs andlor hook and loop
fastening components, although any other known fastening means are generally
acceptable. Some exemplary fastening systems are disclosed in U.S. Patent
3,848,594 entitled "Tape Fastening System for Disposable Diaper" issued to
Buell on November 19, 1974; U.S. Patent B1 4,662,875 entitled "Absorbent
Article" issued to Hirotsu et al. on May 5, 1987; U.S. Patent 4,846,815
entitled
"Disposable Diaper Having An Improved Fastening Device" issued to Scripps on
July 11, 1989; U.S. Patent 4,894,060 entitled "Disposable Diaper With Improved
Hook Fastener Portion" issued to Nestegard on January 16, 1990; U.S. Patent
4,946,527 entitled "Pressure-Sensitive Adhesive Fastener And Method of
Making Same" issued to Battrell on August 7, 1990; and the herein before
referenced U.S. Pat. No. 5,151,092 issued to Buell on September 9, 1992; and
U.S. Pat. No. 5, 221,274 issued to Buell on June 22, 1993. The fastening
system may also provide a means for holding the article in a disposal
configuration as disclosed in U.S. Pat. No. 4,963,140 issued to Robertson et
al.
on October 16, 1990. Each of these patents is incorporated herein by
reference.
The diaper 20 may also comprise side panels 30. The side panels 30
may be elastic or extensible to provide a more comfortable and contouring fit
by
initially conformably fitting the diaper 20 to the wearer and sustaining this
fit
throughout the time of wear well past when the diaper 20 has been loaded with
exudates since the elasticized side panels 30 allow the sides of the diaper 20
to
expand and contract. The side panels 30 may also provide more effective
application of the diaper 20 because even if the diaperer pulls one
elasticized
side panel 30 farther than the other during application, the diaper 20 will
"self-
adjust" during wear.
While the diaper 20 of the present invention preferably has the side
panels 30 disposed in the second waist region 38, the diaper 20 may be
provided with side panels 30 disposed in the first waist region 36 or in both
the
first waist region 36 and the second waist region 38. The side panels 30 may
be
constructed in any suitable configurations. Examples of diapers with
elasticized
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23
side panels are disclosed in U.S. Patent 4,857,067, entitled "Disposable
Diaper
Having Shirred Ears" issued to Wood, et al. on August 15, 1989; U.S. Patent
4,381,781 issued to Sciaraffa, et al. on May 3, 1983; U.S. Patent 4,938,753
issued to Van Gompel, et al. on July 3, 1990; the herein before referenced
U.S.
Pat. No. 5,151,092 issued to Buell on September 9, 1992; and U.S. Pat. No. 5,
221,274 issued to Buell on June 22, 1993; U.S. Patent No. 5,669,897 issued to
LaVon, et al. on September 23, 1997 entitled "Absorbent Articles Providing
Sustained Dynamic Fit'; U.S. Patent Application Serial No. 08/155,048 entitled
"Absorbent Article With Multi-Directional Extensible Side Panels" filed
November 19, 1993 in the names of Robles, et al.; each of which is
incorporated
herein by reference.
The diaper 20 preferably further includes leg cuffs 32 which provide
improved containment of liquids and other body exudates. Leg cuffs may also be
referred to as leg bands, side flaps, barrier cuffs, or elastic cuffs. U.S.
Patent
3,860,003 describes a disposable diaper which provides a contractible leg
opening having a side flap and one or more elastic members to provide an
elasticized leg cuff (a gasketing cuff). U.S. Patent Nos. 4,808,178 and
4,909,803
issued to Aziz et al. on February 28, '! 989 and March 20, 1990, respectively,
describe disposable diapers having "stand-up" elasticized flaps (barrier
cuffs)
which improve the containment of the leg regions. U.S. Patents 4,695,278 and
4,795,454 issued to Lawson on September 22, 1987 and to Dragoo on January
3, 1989, respectively, describe disposable diapers having dual cuffs,
including
gasketing cuffs and barrier cuffs.
The diaper 20 embodiment of the present invention may be applied to a
wearer by positioning one of the waist regions, preferably the rear waist
region
38, under the wearer's back and drawing the remainder of the diaper 20
between the wearer's legs. The other waist region, preferably the front waist
region 36, is positioned across the front of the wearer. The diaperer then
wraps
the side panels 30 around the wearer such that the front waist region 36 and
the
rear waist region 38 are in an overlapping configuration. The side panels 30
will
typically be extended and tensioned during this operation so as to conform to
the size and shape of the wearer. The fastening system 40 is secured to effect
a
side closure.
